Dissociation Between Long-term Weight Loss Intervention and Blood Pressure: an 18-month Randomized Controlled Trial.

Background: Obesity is associated with elevated blood pressure (BP). In patients with obesity and hypertension, weight loss lowers BP, but the long-term effect of weight loss on BP is less clear.

Objective: We aimed to assess the effect of long-term weight loss intervention on BP in normotensive and hypertensive subjects.

Design: Randomized controlled trial.

Participants: Two hundred seventy-eight subjects (mean age 47.9 ± 9.3 years, 89% male, 56% hypertensive) with abdominal obesity or elevated serum triglycerides and low high-density lipoprotein cholesterol were recruited.

Intervention: Eighteen-month weight loss intervention.

Main Measures: Body weight and BP were measured at baseline, after 6 and 18 months.

Results: After 6 months of intervention, in the weight loss phase, body mass index (BMI) decreased by an average of -2.2±1.5 kg/m (p<0.001) and both diastolic BP (DBP) and systolic BP (SBP) decreased by -2.1±8.8 mmHg and -2.3±12.9 mmHg, respectively (p<0.01 for both). The change in BMI was similar in normotensive and hypertensive subjects (-2.0±1.6 and -2.3±1.5, p = 0.246). However, DBP and SBP decreased significantly (-5.2±7.1 mmHg and -6.2±12.5 mmHg, respectively, p<0.001 for both) in hypertensive subjects, and increased in normotensive subjects (1.8±9.3 mmHg, p = 0.041 and 2.7±11.7 mmHg, p = 0.017, respectively). After 18 months, in the weight maintenance phase, BMI slightly increased (0.9±1.3 kg/m, p<0.001) but remained significantly lower than at baseline (p<0.0001). Unlike BMI, DBP and SBP increased significantly in hypertensive subjects (p<0.001) and returned almost to baseline levels.

Conclusion: Weight-loss intervention reduced BP in hypertensive patients, but this was not maintained in the long run.

Clinical Trial Registration: ClinicalTrials.gov Identifier: NCT01530724.